Collating system

ABSTRACT

A collating apparatus for assembling a magazine from a plurality of signatures has a conveyor movable successively through a plurality of signature feeding stations and includes equipment for sensing and counting malfunctions of each feeding station. The counter is periodically reset after a predetermined number of machine cycles; if the number of malfunctions exceeds a preset stored limit before the counter is reset, the machine is stopped automatically. A rejection station following the last signature feeding station rejects magazines for which any of the feeders sensed a malfunction. An inspection station following the rejection station senses the presence or absence of a magazine and compares the results with a malfunction-data record to monitor the performance of the rejection station. One or more feeding stations may be switched to a mode of operation in which a single malfunction instead of an unacceptable fault rate stops the machine.

United States Patent Wise et al. Sept. 2, 1975 [5 COLLATING SYSTEM [57] ABSTRACT [75] Inventors: J3m es wise; Leonard Miaskoff; A collating apparatus for assembling a magazine from Dav'd Reed all of Easton a plurality of signatures has a conveyor movable suc- 73 Assignee; H i J t -t Corporation, cessively through a plurality of signature feeding sta- Cleveland, Oh tions and includes equipment for sensing and Counting malfunctions of each feeding station. The counter is [22] Flled: May 1973 periodically reset after a predetermined number of [21] A pl. No.: 357,602 machine cycles; if the number of malfunctions exceeds a preset stored limit before the counter is reset, the machine is stopped automatically. A rejection station [52] US. Cl. 270/58 following the last signature feeding Station rejects [51] Int. Cl. B65h 39/02 magazines for which any of the feeders sensed a 1 [58] Field of Search 270/54, 58; 209/74 function. An inspection station following the rejection 209/74 M; 271/57 263 station senses the presence or absence of a magazine and compares the results with a malfunction-data re- [56] References C'ted cord to monitor the performance of the rejection sta- UNITED STATES PATENTS tion. One or more feeding stations may be switched to 3,229,599 1/1966 Lowe 93/93 a mode of Operation in which a Single malfunction 3,5l9,264 7/1970 Beacham et al. 270/58 stead of an unacceptable fault rate stops the machine. 3,578,3l0 5/1971 Carson, Jr 270/54 3,608,888 9/1971 McCain et al. 2.70/54 3,692,298 9/1972 Peacock 270/58 X Primary ExaminerRobert W. Michell Assistant Examiner-Vance Y. Hum

17 Claims, 5 Drawing Figures PATENTEUSEP mews 3.902708 SHEET b [1F d l I l l I l ullellllli Tl|||l1l1lHH||||lW||l||J Qwjmmsfiu MQMRQEwMmmQN N3 QMR$ Q Md 3 ll L I IA I I I 1 l I: ll m l I l l I l I I 1 l l l I [FL l! 1 r 1 COLLATING SYSTEM BACKGROUND OF THE INVENTION The present invention relates to a collating apparatus having a plurality of hoppers or feed stations at which signatures are fed to a conveyor, with each station being controlled to feed or not to feed a signature in accordance with commands received from a'computer.

The invention is an improvement in collating systems, and in particular an improvement in a collating system disclosed in US. patent application Ser. No. 14 l ,33 l filed May 7, 1971. In that system various mag azines or books composed of various predetermined combinations of signatures are made in accordance with various subscriber information under the control of a computer. On the basis of information read from a magnetic tape, the computer instructs different ones of the feed stations to feed or not to feed to provide differently constituted magazines for different subscribers. At each feeding station, the performance of the feeder in properly adding one signature is sensed, and a malfunction code is generated when the feeder does not operate properly. The malfunction code is shifted through a shift register to simulate the movement of the defective magazine through-the remaining stations of the gatherer to a reject station and the magazine is rejected when it arrives at the reject station.

In another gatherer of the prior art, described in US. Pat. No. 3,525,516, issued Aug, 25, 1970, to T. W. Bushnell, et al, the gatherer is automatically stopped if a feed device repeatedly malfunctions for a predetermined number of successive machine cycles. The fact that the predetermined number of successive malfunctions occur is detected by a logic gate having inputs from a number of successive stages of a shift register in which the malfunction codes are stored.

SUMMARY OF THE INVENTION The present invention relates to a collating appparatus having a plurality of feed stations at which signatures are added to a conveyor, with each station being controlled to feed or not to feed a signature in accordance with commands received from a computer. At each feed station, malfunctions of the feeder are detected, the type of detectable malfunctions preferably including a miss, which is a failure to feed any signature, and a douuble, which is the feeding of more than one signature. The number of misses and the number of doubles committed by each feeder are counted in the computer. Preferably, each counter is reset to zero and starts counting anew after a predetermined total number of routine machine cycles, forexample, 1,000 cycles. If the number of malfunctions which has been accumulated in a counter during 1,000 machine cycles ever reaches a preset limit number which was previously programmed into the memory of thecomputer, the collating machine is stopped automatically. Thus, the collating machine is stopped if the fault rate is too high.

Two preferred embodiments of the invention are de scribed herein, which differ in that, in the second embodiment, more tasks are performed by a computer than in the first embodiment. In the first embodiment,

when a fault is detected, a chain space of the conveyordownstream feeder from feeding a signature to it. If a downstream hopper does not feed because of the ,downstream shutoffjust described, or because it is prochain space through the machine and prevents each' grammed by the computer not to feed for that particular subscriber, the abstention from feeding is not counted as a fault by the computer, The computer actuates a reject gate to reject the defective magazine when the chain space which the defective magazine occupies arrives at the reject gate station following the last hopper.

The computer and its shift register continue to track every chain space beyond the reject gate to another station, where an automatic inspection is made for pres ence or absence of a magazine. If the reject gate mal functioned by failing to reject a defective magazine, that failure to reject stops the collating apparatus im mediately. Similarly, if the reject gate malfunctioned by rejecting a magazine which was not defective, that malfunction of the reject gate also stops the collating apparatus immediately.

One or more individual feeders can be placed by the operator under standard control in which only one malfunction at that feeder stops the collating machine, or, if desired, two or more consecutive malfunctions can stop it, as in the prior art. Programming of whether or not each hopper should feed can also be taken away from computer control and controlled insteadby manual switches.

Accordingly, one principal object of the present invention is to provide a collating system for forming a magazine or book comprising a gatherer conveyor receiving signatures from a plurality of feeding stations, equipment for sensing a malfunction at each signature feed station, and apparatus for counting the malfunctions for a predetermined number of machine cycles, and comparing the count with a maximum acceptable number of malfunctions for each feed station.

A further object is to provide a system as above in which both misfed and double-fed signatures are sensed at each hopper and the number of each is separately counted and compared with a limit.

Another principal object is to provide a collating system for forming a magazine or book having a gatherer conveyor moving through a plurality of signature feeding stations and past a reject station, and in which a malfunction at a feed station produces a reject code signal which is stored until the imperfect magazine arrives at a reject station where the, magazine is rejected, and including an inspection station following the reject station for ascertaining whether or not the reject station properly rejected or properly retained each book.

A further object is to provide a system as immedi ately above and in which improper rejections and improper retentions at the reject station stop the collating apparatus.

A further principal object of the invention is to provide a system for producing different magazines composed of different predetermined combinations of signatures in accordance with different subscriber information, and in which individual hoppers may be selectively controlled to operate in either of two modes: (a) a firstmode in which a malfunction of a feed station is sensed andstops the machine, or (b) a second mode in whichmalfunctions of hoppers. are counted and stop A further object is to provide a system as above in which commands for some of the plurality of feeders are under manual control and commands for the other feeders are under computer control, and each feeder can be selectively controlled to feed or not to feed under either type of control.

DESCRIPTION OF TI-IE FIGURES Other objects and features of the invention will become apparent upon consideration of the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 shows a collating machine including a conveyor, a plurality of signature feeding stations, at rejection station. and an inspection station;

FIG. 2 is a block diagram ofa programmable controller which receives instructions from a computer and which controls the collating machine of FIG. 1;

FIG. 3 is a simplified block diagram of the computer which cooperates with the programmable controller of FIG. 2 to control the collating machine of FIG. 1;

FIG. 4 is a symbolic block diagram showing a portion of a memory unit of the computer of FIG. 3 and some logic functions performed by the computer; and

FIG. 5 is a block diagram of a second embodiment in which the computer performs some of the operations that were performed in the first embodiment by the programmable controller.

DESCRIPTION OF PREFERRED EMBODIMENTS In a first preferred embodiment of the invention. a collating or gathering machine for assembling magazines and books from a plurality of signatures is ar ranged to be controlled by a programmable controller which in turn is under the direction of a digital computer so that the machine can provide different combinations of signatures for different subscribers. The computer (FIG. 3) is preferably programmed in advance, after which it receives subscriber data from a reel of magnetic tape or other source of input information. The magnetic tape contains data describing the particular different sets of signatures which are to be employed by the collating machine 14 (FIG. 1) to form a magazine tailored differently for various groups of subscribers.

The computer 10 does not operate directly upon the collating machine 14, but instead issues its instructions and receives information back from the programmable controller 12, (FIG. 2). The programmable controller 12 implements the instructions issued by the computer 10 to control the collating machine 14 to produce the various desired types of magazines. Thus, a magnetic data tape file containing subscriber data indirectly controls the collating machine 14 to produce the desired magazines. The computer 10 is a conventional and well-known model PDP-8 computer complete with convention commerciallyavailable interface equipment for it manufactured by the Digital Equipment Corp. of Maynard, Massachusetts.

The collating machine has a conveyor chain 16 onto which different signatures are fed from hoppers to form a desired magazine, after which any defectively formed magazines are rejected at a rejection station, the performance of the rejection station being monitored at a subsequent inspection station. As shown in FIG. I, the conveyor chain 16 is divided longitudinally into chain spaces, each of which is large enough to accommodate a magazine to be assembled on the chain space. The conveyor chain 16 moves through a plurality of feeding stations. A signature feeder or hopper is located at each feeding station. The number and construction of the feeders or hoppers may vary, but preferably the feeders are as shown in US. application Ser. No. 339.144, assigned to the assignce of the present invention. That disclosure is incorporated herein by reference.

In general, each feeder includes, as is well known, a hopper which contains a supply of signatures. The signatures are removed from the hopper by a suitable mechanism which includes a suction device which withdraws an edge of a signature downwardly into a position where it can be gripped by a gripper which is car ricd on a rotatable drum. The gripper, once it grips the signature, carries the signature with the drum to a release location where the signature is released for deposit into the chain space.

As noted, the number of hoppers or feeders may vary and in the preferred embodiment there are 32 hoppers 18a, 18b, etc., for feeding signatures onto the chain. Each of the hoppers 18a, 1812, etc., has a supply of sig natures which differ among hoppers, and each hopper is capable of feeding one signature at a time onto the chain 16 when a respective feed device 20a, 20b, 200, etc., of the hopper is actuated.

Each hopper has a respective caliper means 22a, 22b, etc., for measuring the thickness of a signature which isfed during each machine cycle. The caliper device actuates a first switch called the miss switch 24a, 24b, etc., if no signature is fed, and it actuates a second switch 26a, 2617, etc., if two or more signatures are fed. Under some circumstances but not all, an abstention from feeding represents a malfunction, so that actuation of the miss switch 24 may indicate a malfunction. Actuation of the doubles switch 26 always indicates a malfunction of a signature feeder. Each chain space, as it comes out of the last stage of the gatherer 18, carries a magazine. Some of the magazines are defective, as indicated by information obtained from the miss switches 24 and the doubles switches 26. When a defective magazine reaches a reject station 28, it is removed from the conveyor chain 16 by the operation of a reject actuator 30 which is under the control of the programmable controller 12.

At a later station 32, each chain space is inspected for the presence or absence of a magazine in order to monitor the performance of the reject station 28. The inspection station 32 includes a lamp 34 projecting a beam of light 36 across the chain space to a photocell 38, which receives light if and only if a magazine is present at the chain space. The inspection station 32 supplies a signal to the programmable controller 12 which stops the collating apparatus immediately upon a malfunction of the rejection station and which provides information to the computer 10 for counting wrongful absences of magazines and for counting wrongful presences of magazines at the inspection station 32, that is, for counting both types of errors which could occur at the rejection station 28.

In this way, the collating machine 14 selectively feeds signatures at a plurality of hoppers onto a conveyor chain 16, with the misses and double feeding of signatures detected at each hopper by a caliper, and defective finished magazines are rejected at a rejection station 28, and the performance of the rejection station 28 is monitored at the inspection station 32. At the rejection station a suitable means is provided for rejecting the defective magazines. Details of the mechanism will not be described, since any known reject structure can be utilized.

In the first preferred enbodiment the programmable controller 12 performs many functions. It stores data describing the pattern of signatures which are to be fed at the various hoppers, receives malfunction data from the caliper switches 24 and 26, and shifts that data through shift registers to simulate movement of the books through the collating machine 14, issues reject signals to the reject station 28, and receives data from the inspection station 32 for retransmission to the com puter 10. Binary data specifying which hoppers should feed signatures for producing a particular type of magazine for one particular group of subscribers is received by the programmable controller 12 on data lines 40 and stored in latching relays 42a, 42b, 42c, etc. corresponding respectively to the hoppers 18a, 18b, 18c, etc.

If a signature is to feed at, for example, hopper 18b, a pair of contacts 44b of the relay 42b are placed in a closed position and they connect a voltage from a voltage supply 46 to the feeder actuator b of hopper 18b through a chain of switch and relay contacts 48b, 50b, 52b, whose various individual functions are to be described later. If all of the contacts 48b, 50b, 52b are closed, the actuator 20b causes a signature to feed at the station 1811 onto the conveyor chain 16.

Signals on the cable al, FIGS. 1 and 2, actuate the feed devices 20a, 20b, 206, etc., to feed or not to feed a signature, using mechanisms and methods that are well-known in the prior art. One such known method of controlling feeding, for example, is to turn a vacuum suction system on or off at the hopper at a proper time to pick up a signature or not to pick up a signature for feeding.

Voltages applied to the various conductors of a multiple-conductor cable 54 on a line a2 of FIGS. 1 and 2 serve to enable and disable the miss switches 24 and the doubles switches 26 of FIG. I. In this way, the miss switches and doubles switches are selectively con trolled to prevent them from generating a reject signal when a hopper is intentionally inhibited from feeding a signature.

If the signature feeds properly, the caliper 2212 does not actuate either the miss switch 24b or the doubles switch 26b. If the signature does not feed at all, however, the caliper 22b closes the contacts of the miss switch 24b. This connects an electrical signal, which was received from one of the switches 52 on the cable 54, through the miss switch 24b, and from there through a phase delay device 56b and an OR gate 58b, into a second stage 6017 of a shift register 60 which keeps track of the miss signals. The miss signal which is thus stored in stage 60b is later transmitted to the next succeeding stage 6()(' upon the next machine cycle, the machine cycle being indicated by a pulse produced by a synchronizer 62 and a polyphase slaved clock 64, which shifts the shift register 60. The synchronizer 62 is a sensing device which produces one output pulse signal for each machine cycle of the collating machine 14. When it is being shifted, the malfunction signal in stage 60 [7 passes through an OR gate 580 into the stage 60c of the shift register 60. The shifting is repeated cyclically. All strobe signals are omitted from the diagrams. I

When the malfunction signal arrives at a later station 60R of the shift register 60, the defectively produced magazine which resulted from the misfeed at station 18b is then located at the reject station 28, and the re- 5 ject actuator 30 is actuated by the malfunction signal in stage 60R, which is communicated to the reject ac tuator 30 through an OR gate 62. Thereupon, the defective magazine is removed from the conveyor chain 16 by the reject actuator 30.

The malfunction signal remains in the shift register 60, and upon the second following machine cycle, the malfunction signal is in a stage 601, where it is available for comparison with photocell data received from the inspection station 32. No magazine should then be present at the inspection station 32 if the reject station 28 properly rejected the defective magazine'two cycles earlier. I

In a similar manner, when a feeder feeds two signatures instead of one, the malfunction is detected by a caliper and entered as a code signal into another shift register 64, which thereafter shifts the malfunction code signal to successive stages of the register 64 upon successive machine cycles. The code signal subsequently arrives at a stage 64R, where it is capable of actuating the reject actuator 30 through the OR gate 62. Two machine cycles later, the malfunction code is in a stage 641 of the register 64. The presence of a malfunc tion code in the stage 64I should coincide with the absence of a magazine at the inspection station 32, because the reject station 28 should have removed the de fective magazine. Further description of the operation of the inspection station 32 is provided hereinbelow.

When a malfunction of a hopper feeder occurs, the downstream hoppers are prevented from feeding signatures onto the particular chain space which carries the defective magazine. This downstream shutoff of feeders is accomplished by the switches 50b, 52b, FIG. 2. The switch 52b is actuated to an open position by a register read device 66b when the respective shift register stage 60b contains a logic 1 signal, which indicates that a defective book is then present at the hopper 18b. The open contacts of the switch 52b prevent the actuator 1812 from operating in the current machine cycle, so that no signature is fed onto the defective magazine at hoppers downstream from a hopper where the ma]- function occurred. The switch SOb performs a similar function for double-feed malfunctions of an upstream hopper by opening its switch contacts in response to the presence of a malfunction code signal in the stage 64b of the doubles shift register 64.

If it is desired to operate one or more hoppers under the control of a manual switch instead of the computer 10, a manual-orautomatic selector switch 48a, 48b, 48c, etc. is first actuated to its manual position. For example. switch 48b would be actuated to a position 68b. The hopper 18b is thereafter controlled to feed or not to feed in accordance with whether a manual switch 70b is closed or open, the switch 70b substituting for the contacts 44b.

Preferably, the switch 701) has two other pairs of contacts 72b and 74b, shown at the top of FIG. 2, which, when closed, connect the fault signals from the miss switch 24b and the doubles switch 26b to an OR gate 76 whose output actuates a stop relay 78. The stop relay 78 interrupts a run contactor 80 to stop the machine upon the first occurrence of either a misfeed or a double feed fault at hopper 18b, or indeed any hopper at which the manual-or-automatic switch 48 is in the manual position.

Other embodiments of these switch circuits are readily achieved and have been used in the prior art. For example, the occurrence of two successive faults at a particular hopper can stop the collating machine 14 when a respective manual-or-automatic switch 48 is in the manual position, which could be termed the standard position because its corresponding mode of op eration is old. If desired, the switch contacts 72h, 74/2 may be arranged to be opperated independently of the manual-or-automatic switch 48.

In a first portion of each machine cycle, both the miss shift register 60 and the doubles shift register 64 are read, and their corresponding switches 52, 50 are set in positions in accordance with the data in those shift registers. Also, the hopper feeders 18a, 18b, etc. are actuated, and the misses and doubles switches 24, 26 are operated to produce new fault data if a malfunction occurs. In a later portion of the same machine cycle, following a phase delay introduced by the phase delay devices 56, 57, the new fault data from the switches 24, 26 are entered into the respective shift registers 60, 64, following which the data in those shift registers are shifted to the next succeeding stage in response to a pulse on a line 82 from the slaved polyphase clock 64.

Fault signals from the miss switches 24 and from the doubles switches 26 are also transmitted, over cables 84, 86 respectively, from the programmable controller 14 to the computer 10, where the faults are counted in a manner to be described hereinbelow.

If desired, the gatherer 18 may be divided into sections having four hoppers per section, with a different synchronizer 62 for each section, and with the various sections mechanically driven out of phase with each other to distribute the torque load on a driving motor more uniformly throughout a machine cycle. The techniques involved in using more than one synchronizer are known in the prior art.

The inspection station 32 of FIG. 1 cooperates with portions of the programmable controller 12 to produce an output pulse at an output line 88 of FIG. 2 whenever a magazine should be present but is not present at the inspection station, for use by the programmable controller 12 to stop the collating machine 14 immediately, and for use by the computer. The computer counts these occurrences, which can be due to a malfunction of the reject station 28. The inspection station 32 also produces an output pulse at another output line 90 of FIG. 2 when a magazine in present at the inspection station 32 which should have been rejected at the reject station 28, which also stops the collating machine 14 and is counted.

The wrongful absence signals at the output line 88 are produced by the output of a logic gate 92 when one of the gates input terminals 92a has a logic 1 signal indicating that the photocell 38 is receiving light in consequence ofthe absence of a signature at the station 32. Simultaneously, another input terminal 92b is receiving a logic zero signal, indicating that neither the stage 60l of the miss shift register 60 nor the stage 641 of the doubles shift register 64 contains a malfunction logic 1 signal. The signals from the stages 60l and 64l are combined in an OR gate 94 so that either could have, but did not, produce a logic 1 signal at the terminal 921). The signal at terminal 921) is inverted and connected in a logic AND relationship with the signal at terminal 92a. Thus, if the shift registers 60 and 64 indicate that there is no defect at the chain position presently at the inspection station 32, and at the same time the inspection station photocell 38 indicates that the magazine has been removed from that chain station, a wrongful absence signal is produced at the output terminal 88 and transmitted to the computer 10 to be counted. The signal at the terminal 88 is also connected to the OR gate 76 to stop the collating machine 14.

In a similar way, if a book is present at the chain station 32, thereby producing a zero logic signal at an inversion terminal 960 of a logic gate 96, and on the same machine cycle another terminal 96b of the logic gate 96 has a logic 1 signal indicating that one or both of the stages 60l, 64] is indicating a defective magazine at the chain space 32, a wrongful presence signal is produced on the line for transmission to the computer 10 where it is counted. The signal on the line 90 is also connected to the OR gate 76 to stop the collating machine 14. The technique by which events are counted by the computer 10 is described hereinbelow following a general description of the main components of the computer.

The computer 10 includes an input/output interface unit 98, a memory unit 100, an arithmetic unit 102, and a control unit 104. Major communication routes between the units of the computer are shown in the greatly simplified block diagram of FIG. 3. The input- /output interface unit 98 represents inputs and outputs of the computer 10 from any of a variety of sources and destinations. Program instructions are entered into the computer at a terminal 980 of block 98. Also certain parameter values, such as the maximum permissible number of misses per 1000 cycles for each hopper, and the maximum permissible number of double feeds per 1000 cycles of machine operation for each hopper are entered at terminal 98a and stored in the computers memory unit IOO before the collating machine 14 is started. After the computer has been thus programmed, subscriber data specifying the signatures to be used in forming magazines for a first group of subscribers is entered into the computer at terminal 98a, preferably from a magnetic tape file. Other sources of input data can be employed, of course, including punched paper tape, punched cards, or a manually operated keyboard instrument.

When a hopper error rate is found to be excessive, as further discussed below, the input/output interface unit 98 transmits a stop signal from the computer 10 to the programmable controller 12 on a line 105 to stop the collating machine 14. If desired, the input/output interface unit 98 may also print out information concerning the operation of the collating machine 14 on a teleprinter. Other output devices which may be used are paper tape, punched cards, and magnetic tape.

The memory unit 100 stores program instructions for use by the control unit 104, data for use by the arithmetic unit 102, and instructions and data for use by the programmable controller 14. Preferably, the memory unit 100 is a random access storage device such as an array of toroidal magnetic cores which store binary data by being magnetized in either a clockwise or a counterclockwise direction. The memory unit is preferably capable of storing more than 1000 words, each of which is 12 bits long, typically. Each word space of data storage is identified by an address so that data can be written into the space or read out of it by addressing that location.

The arithmetic unit 102 performs the computations that must be done by the computer. In the present invention, the counting of errors and the counting of machine cycles are performed by the arithmetic unit in cooperation with the memory unit. The principal component of the arithmetic unit is an accumulator which can accumulate partial sums during arithmetical computations and which, among other things, can count events such as malfunction-indicating pulses. To count, the computer reads the previously accumulated count from memory upon occurrence of an event to be counted then increments that data by one unit, and then transfers the new amount out of the accumulator and back into the memory unit for storage again in the same location from which it was previously read.

The control unit 104 is a switching section which manages the operations of the computer 10. The control unit 104 withdraws programmed instructions in an orderly manner from the computer memory unit 100 and uses those instructions to control the arithmetic unit 102, the memory unit 100, and the input/output interface 98. The control unit 104 issues commands to the arithmetic unit 102 to tell it what to do and to tell it from what addresses in the memory unit it should obtain the data upon which it is to operate. When the arithmetic unit 102 has completed a task, the control unit 104 instructs the arithmetic unit as to what to do with the results, for example, to store the results in a particular address of the memory unit 100 for subsequent use.

Some of the contents of the memory unit 100 are in dicated symbolically in FIG. 4 for the first preferred embodiment. The contents include program instructions stored in a group of storage locations 106, each of which accommodates one word.

Hopper data that is stored in the memory 100 in cludes feed commands stored in a group of memory 10- cations 108. These particular core addresses 108 contain instructions to the hoppers 18, to control whether or not their feed devices a, 20b, 20c, etc. should feed a signature. Hence, the feed commands in the storage locations 108 specify the makeup of a particular type of magazine for a subscriber whose magazines are currently being assembled by the collating machine 14.

The hopper data also includes, in storage locations 110, the count of the number of miss malfunctions that have occurred thus far for each hopper in the current 1000-cycle interval. On FIG. 4 the number of misses for the first hopper is designated A and the number of misses for the 32nd hopper is designated A The maximum number of misses for any hopper, at which number the collating machine will be stopped, is

stored for each hopper in storage addresses 112. This could be called the maximum fault rate per 1000 cycles for misses. The maximum number for hopper 1 is designated P and for hopper 32, P

The numbers A A are reset to Zero at the end of each 1000 machine cycles, although some number other than 1000 can be employed if desired.

The number of doubles malfunctions, that is the feeding of two or more signatures when only one should have been fed, is stored for each hopper in storage addresses 114. A represents the number of doubles counted for hopper No. 1 since the start of the 1000 machine cycle interval which is currently in progress,

and A,,' represents the number of doubles for hopper 32. The fault rate limit per 1000 cycles for double feeds is stored in storage locations 116 for each of the 32 hoppers. inthe preferred embodiment. These numbers are denoted P,, for hopper No. l and P,,' for hopper No. 32. The fault rate limits may be different for different hoppers if desired.

Intervals within which the fault rate is determined are established and controlled by data in a count intervals portion of the memory unit 100. The number of machine cycles, for example, 1000, within which misses and doublesiare to be counted before starting over at zero is stored in the memory address 118, labeled 1,. The number of machine cycles that have oc curred thus far in a current 1000 cycle counting interval is stored in the memory location 120, the count being designated by I,,. Thus, for example, at a given instant I,, may be 800 and I ='l000, indicating that 800 machine cycles have occurred thus far in the current 1000 cycle counting interval. To continue the numerical example, the number of misses P which would .stop the collating machine 14 for hopper No. 32 may be set at 3 and this would be stored in the hopper 32 address location 112. After 800 machine cycles in the present example, the number of misses A for hopper 32 may be 2. The number 2 is therefore stored in the address location 110. If, during the next 200 machine cycles, another miss should occur at hopper 32, the number A would then be increased to 3, and the collating machine 14 would be stopped, because the maximum fault rate limit P of3 would have been reached. If, instead, no further misses should occur at hopper 32 within the next 200 machine cycles, the 1000 cycle interval would have come to an end and the count A would be reset to zero without reaching the limit P and therefore without stopping the collating machine 14.

The number of counts 1 accumulated thus far during a count interval are counted by reading the number 1 from the storage location 120, and adding 1 to that amount in a portion 122 of the arithmetic unit 102 upon occurrence of a synchronizing signal 124. After each addition of l to the count I the new count is compared, as indicated by a block symbol 126 of FIG. 4, with the programmed interval length I;- If 1,, does not as yet equal I the new value of I is written back into the storage location to await the next sync signal 124. If, instead, the number I, has been increased to the point that it equals Ip, the block 126 produces a signal 128 to reset I that is to write a zero into the memory location 120. The signal 128 also resets to zero all 32 of the miss counts A A in the storage registers 110, and resets to zero all of the doubles counts A A in the storage locations 114.

Upon occurrence of a miss signal on one of the lines 84 of FIG. 2, the miss count in the storage register 110 for the corresponding hopper is increased by a count of 1. For example, a miss at hopper 32 causes the computer to withdraw the number A from its storage location and to increment it by 1. unit as shown in block 130 of FIG. 4. The increased value of A is then compared in a comparator block 132, which is part of the arithmetic unit 102, with the stored fault rate limit P for the hopper 32. If the fault rate limit has not been reached yet; the new value of A is written back into the storage register 110 for hopper 32. If, however, the fault rate limit has been reached, a signal is transmitted from the circuit 132 to an OR logic function portion 134 of the computer 10. An output signal 134a from portion 134 is connected to the OR logic device 76 in the programmable controller, FIG. 2. to actuate the stop relay 78 and interrupt the run contactor 80 to stop the collating machine 14.

In the same way, when a doubles malfunction occurs, for example for hopper 32, the count A,, in a storage register 114 is read from the memory 100 and incremented in a unit 136 by I count. The new count is compared in a comparator program 138 with the fault rate limit P,,' for that hopper, and if the fault rate limit has been reached. a signal 140 is applied to the OR function device 134 to stop the collating machine 14.

In this way, the computer operates to count the number of faults of each type, that is, misses or doubles, and to stop the collating machine 14 if any of the malfunction counts reaches a maximum permissible value which is stored in the memory unit 100 of the computer The number of wrongful absences WA detected at the inspection station 32 is stored in a memory address 142 of the computer memory, from which it can be accessed upon command for reading by anoperator. The number of wrongful presences WP is similarly stored, in a memory location 144, FIG. 4. The WA and WP counts can be reset to zero by a signal on the line 128 if desired, or can instead be reset by a manually initiated reset command.

A second preferred embodiment of the invention is shown, in part, in FIG. 5, in which more of the functions of the collating apparatus are controlled by software in the computer 10. The programmable controller 12 of FIG. 5, which replaces the programmable controller 12 of the first preferred embodiment, is drawn so as to receive correspondingly labelled cables and lines al, (12, b, c, d, e,f, g, 11, and i from FIG. 1. Thus in the second embodiment FIG. replaces FIG. 2. FIGS. 1, 3, and 4 are applicable to both the first and second embodiments.

In the second preferred embodiment, the programmable controller 12 receives signals from the collating machine and stores them in storage registers, from which the data are read out periodically by a scanning unit and transmitted to the computer 10, which then determines control signals, and transmits the control signals back to the programmable controller 12, which in turn sends them to the collating machine 14. The programmable controller 12 receives input signals from the miss switches 24, the doubles switches 26, the synchronizing device or devices 62, and from the inspection photocell 38. For example, signals from the miss switch 24a of the first hopper are transmitted on a line 0 to a first stage 148a of a misses storage register 148 in the programmable controller 12, and signals from the miss switch 24b of the second hopper are connected by way of a line e to a second stage 14812 of the misses storage register 148, FIG. 5. A read-only memory scan unit 150 scans the stages 148a, I481), etc., of the misses storage register 148 to read the data sequentially therefrom.

The scan unit 150 is a read-only memory unit having very high noise immunity, and is capable, because of semi-permanent internal programming, of performing sequential operations under its own control. The read only memory scan unit 150 and other devices of the programmable controller 12' are known in'the prior art. A typical commercial programmable controller of this type is being manufactured by Digital Equipment Corporation of Maynard, Massachusetts and is known as model PDP-14. Methods for programming the readonly memory unit of the programmable controller 12 are well known.

The array of misses data that is stored in the misses storage register 148 is periodically transmitted through theread-only memory scan unit 150 and through an input/output register 152 to the computer 10. In the computer 10 these data are utilized under the control of program instructions which were previously entered into memory addresses 106 of the memory unit 100 by a software program. The computer determines the proper behavior of the feed devices 20a, 20b, 20c, and determines whether or not to enable each of the miss switches 24 and .doubles switches 26 upon each machine cycle, and determines whether or not to actuate the reject actuator 30 and the run contactor 80. In structions of this sort that are generated by the computer 10 are transmitted to the input/output register 152 of the programmable controller 12, and under the control ofthe read only memory scan unit 150, are connected to an output register 154 of the programmable controller. The output register 154 applies control signals to the lines a1, a2, g, and i to control the feed devices 20, to enable the malfunction switches 24, 26, to operate reject actuator 30, and to trip the run contactor respectively.

The construction and operation of a doubles storage register 156 is similar to that of the misses storage register 148 described above. Signals produced by the doubles switches 26a, 26b, etc., are entered into respective stages 156a, 156b, etc., of the doubles storage register 156. The scan unit 150 sequentially scans the data contents of the doubles storage register 156 at least once for each cycle of collating machine operation and transmits the data which it reads successively therefrom, to an input/output register 152 and thence to the computer 10. Data from the doubles storage register 156 are taken into account along with the data from the misses storage register 148 by the computer 10, in determining and controlling the proper behavior of the collating machine 14. Hopper data such as misses and doubles data are stored in portions, which are not shown, of the memory unit of the computer 10, in a manner similar to their storage in the registers 148, 156.

A sectional synchronizing signal storage register 158 is also included in the programmable controller 12. It periodically receives synchronizing signals from the synchronizing device 62 on a line b, which it enters into a data storage stage 158a. If only one synchronizing device 62 is employed to serve all 32 hoppers of the collating machine, only the first stage 158a of the storage register 158 receives signals upon each cycle of the collating machine 14. If instead, as is preferred, a separate synchronizing device, such as device s of hopper No. 5, is provided for each four-hopper section of the collating machine 14, then signals are periodically provided by these additonal synchronizing devices also, and are stored in additional stages such as a stage 1580 of the sectional sync storage register 158. The separate synchronizing devices are necessary when each four hopper section is out-of-phase with the other four hopper sections. This is the case in the preferred embodiment.

The data stored in the sync register 158 are frequently and periodically scanned by the read-only memory scan unit 150, and transmitted through the in put/output register 152 to the computer 10 for the purpose of synchronizing the command signals which are subsequently issued from the computer 10.

The photocell 38 at the inspection station 32 produces signals which are transmitted on a line /1 to an in spection data storage stage 160 of the programmable controller 12. This binary data is also periodically read from the storage stage 160 by the scanning unit 150, and transmitted to the computer 10. The computer takes this photocell data into account, along with data from the misses storage register 148 and the doubles storage register 156, to determine whether or not the reject station 28 is operating properly, and hence whether or not to stop the collator 14. In the second preferred embodiment the computer performs the same logic operations with regard to the inspection station 32 that were provided by the logic units 92, 94 and 96 of the first embodiment. Just as in the first embodiment, a stop signal is produced when the reject actuator 30 erroneously rejects a book which should not have been rejected, or erroneously retains a book which should have been rejected. Thereupon, in the second preferred embodiment, a command is issued to the programmable controller 12 from the computer 10 which makes the output register 154 issue a stop command signal on the line i to trip the run contactor 80 to stop the collating machine. If desired, the number of faulty operations of the reject station 28 can be counted in the inspection data portions 142, 144 of the computer 10.

Fewer interconnecting lines are required to the in put/output interface 98 of the computer 10, FIG. 5, in the second embodiment because the scanning unit 150 multiplexes the data passing between the computer 10 and the programmable controller 12'.

Software is required for programming the computer 10, including software to perform those functions of the second embodiment that were performed by the programmable controller 12 in the first embodiment. The preparation of the software for performing such clearly defined functions is well within the knowledge of those skilled in the art of programming process control computers and general purpose computers, and will not therefore be elaborated here.

What is claimed is:

l. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor having a plurality of chain spaces movable successively through a plurality of signature feeding stations and past a reject station and adapted to receive signatures at said feeding stations to form a book in each chain space as the chain space moves, a signature feed means at each feeding station for feeding signatures to said gatherer conveyor chain spaces, sensing means for sensing a malfunction at each feeding station which would produce an imperfect book and for producing a status signal upon the occurrence of a mal function, storage means for storing the status signal in response to the sensing of a malfunction at a signature feeding station, means controlled by said status signal for rejecting the imperfect book at said reject station, inspection means for inspecting a chain space beyond said reject station and providing a signal if a book is present in said chain space. and means for comparing the signal from said inspection means with the status signal.

2. A system as defined in claim 1 and further including stopping means responsive to said comparison means for stopping the collating system when a book is present in a chain space from which the book should have been rejected or when a book is absent from a chain space from which the book should not have been rejected.

3. A system as defined in claim 1 and further including counter means responsive to said comparison means for counting the number of times that'a book is present in a chain space from which the book should have been rejected and absent from a chain space in which a book should be present.

4. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book wherein said malfunction comprises either missing the feeding of a signature or the multiple feeding of a signature and said sensor means comprises first means for sensing the missed feeding of a signature and second means for sensing a multiple feeding of a signature, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station including first means for storing a maximum limit number of missed feeding malfunctions and second means for storing a maximum number of multiple feeding malfunctions for the prede termined number of machine cycles, comparison means for receiving and comparing data indicating each number of malfunctions registered in said counting means with the respective stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the respective stored limit number for that station,

5. A collating system for producing different magazines composed of different predetermined combinations of signatures for different groups of subscribers classified in accordance with predetermined subscriber information, the system comprising a gathering machine having a gatherer conveyor with a plurality of chain spaces movable successively through a plurality of signatures feeding stations and adapted to receive signatures at said feeding stations whereby a magazine is formed in each chain space as the chain space moves through the feeding stations, said gathering machine comprising signature feed means at each of said stations, said gathering machine operating in cycles, each cycle of operation causing successive feeding of signatures from at least some of said signature feed means to make up each magazine, each of said signature feed means having instruction means for instructing the associated signature feed means to feed or not feed dur ing each gathering machine cycle, file means for storing information in machine readable form identifying different subscribers with different predetermined combinations of at least some of said signature feed means to be instructed to feed during a machine cycle to provide the predetermined combination of signatures constituting the appropriate magazine for each subscriber, read ing means for reading said file means and instructing feeding of said signature feed means in the predetermined combination required to provide the different magazines appropriate for the corresponding subscribers, manual switching means for each instruction means for disconnecting said reading means from said instruction means for each signature feeding means, and further comprising sensing means for sensing malfunctions separately at each of said signature feeding stations, and producing status signals accordingly, computer means comprising means receiving information based upon said signals for computing for each of said stations a rate of occurrence of malfunctons for a predetermined number of counted cycles of said gathering machine, said computer means further comprising means for computing when said rate of occurrence reaches a predetermined and stored limit, and first stopping means for stopping the system when said predetermined limit is reached, said system further comprising second stopping means responsive to said status signals for stopping the system when said sensing means senses a predetermined number at least one of successive malfunctions at a signature feeding station, and means for disabling said first stopping means and enabling said second stopping means upon actuation of said switching means to feed signatures when said signature feeding means is disconnected from said reading means, and further including storage means for storing said status signals, means controlled by said status signals for rejecting an imperfect book at a reject station, inspection means for inspecting a chain space beyond said reject station and providing a signal if a book is present in said chain space, and comparison means for comparing the signal from said inspection means with the status signal.

6. A collating system for producing different magazines composed of different predetermined combinations of signatures for different groups of subscribers classified in accordance with predetermined subscriber information, the system comprising a gathering machine having a gatherer conveyor with a plurality'of chain spaces movable successively through a plurality of signatures at said feeding stations whereby a magazine is formed in each chain space as the chain space moves through the feeding stations, said gathering machine comprising signature feed means at each of said stations, said gathering machine operating in cycles, each cycle of operation causing successive feeding of signatures from at least some of said signature feed means to make up each magazine, each of said signature feed means having instruction means for instructing the associated signature feed means to feed or not feed during each gathering machine cycle, file means for storing information in machine readable form identifying different subscribers with different predetermined combinations of at least some of said signature feed means to be instructed to feed during a machine cycle to provide the predetermined combination of signatures constituting the appropriate'magazine for each subscriber, reading means for reading said file means and instructing feeding of said signature feed means in the predetermined combination required to provide the different magazines appropriate for the corresponding subscribers, and further comprising sensing means for sensing malfunctions separately at each of said signature feeding stations, computer means comprising means for computing for each of said stations at rate of occurrence of malfunctions for a predetermined number'of gathering machine cycles, said computer means further comprising means for computing when said rate reaches a predetermined limit, and first means for stopping the system when said predetermined limit is reached.

7. A collating system as defined in claim 6 and further comprising manual switching means for each instruction means for disconnecting said reading means from said instruction means for each signature feeding m'eans. second means for stopping the system when said sensing means senses a predetermined number at least one ofsuccessive malfunctions at a signature feeding station, and means for disabling said first stopping means and enabling said second stoppping means upon actuation of said switching means to feed signatures when said signature feeding means is disconnected from said reading means. i

8. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively'through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfuncton at each signature feeding station which would produce an imperfect book, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and wherein said malfunction comprises either missing the feeding of a signature or multiple feeding of a signature, and said sensor means comprises first switch means for sensing the missed feeding of a signa ture and second switch means for sensing the multiple feeding ofa signature, and wherein said means for storing a maximum limit number includes means for storing a limit number of missed signatures and a limit number of multiple-fed signatures for each station, means for separately counting the number of missed signatures and the number of multiple-fed signatures at each station, and means for separately comparing the counts of missed signatures and multiple-fed signatures at each station with their respective stored limit numbers for stopping the system upon reaching the respective limit number.

9. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book, counting means for registering and counting the senscd'malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of'malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and wherein said counting means and said comparison means comprise digital computer means.

10. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station. sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book, counting means for regis tering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and feed control means for controlling said signature feed means to feed or not to feed a signature to said gatherer conveyor at each station, said feed control means including digital computer means for controlling said feed control means at each station.

11. A collating system as defined in claim and wherein said feed control means further comprises manually settable means for controlling said signature feed means to feed or not to feed, including selection means for individually placing said signature feed means either under control of said digital computer means or under control of said manually settable means.

12. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing occurrence of a malfunction feed at each signature feeding station which would produce an imperfect book, first counting means for counting a predetermined number of machine cycles, second counting means for registering and counting the number of sensed malfunction feeds during said predetermined number of machine cycles, said second counting means being capable of registering and counting said malfunction feeds when said malfunction feeds occur non-contiguously among intervening correct feeds, data storage means for each feeding station for storing a maximum limit number of malfunction feeds for said predetermined number of machine cycles, comparison means for comparing said stored limit number with data indicating said number of malfunction feeds registered in said second counting means since the start of said predetermined number of machine cycles, and means responsive to said comparison means for stopping the system when the number of malfunction feeds which occurred at any station equals the stored limit number for that station.

13. A collating system as defined in claim 12 further including feed control means for controlling said signature feed means to feed or not to feed a signature to said gatherer conveyor at each station.

14. A collating system as defined in claim 12 and wherein said malfunction comprises either missing the feeding ofa signature or the multiple feeding of a signature, and said sensor means comprises first switch means for sensing the missed feeding of a signature and second switch means for sensing the multiple feeding of a signature.

15. A collating system as defined in claim 12 and wherein said first counting means comprises means for resetting said second counting means to start its count anew when said predetermined number of machine cycles is reached.

16. A collating system as defined in claim 12 and fur ther comprising shutdown means responsive to said sensing means to actuate said means for stopping upon occurrence of a predetermined number at least one of uninterrupted successive malfunctions at each individual feeding station, and switching means for each indi vidual feeding station for selectively making said means for stopping responsive either to said comparison means or to said shutdown means.

17. A collating system as defined in claim 12 and wherein said second counting means comprises means capable also of registering and counting malfunction feeds that occur contiguously without intervening correct feeds, whereby said number of malfunction feeds registered in said second counting means includes both non-contiguous and contiguous malfunction feeds. 

1. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor having a plurality of chain spaces movable successively through a plurality of signature feeding stations and past a reject station and adapted to receive signatures at said feeding stations to form a book in each chain space as the chain space moves, a signature feed means at each feeding station for feeding signatures to said gatherer conveyor chain spaces, sensing means for sensing a malfunction at each feeding station which would produce an imperfect book and for producing a status signal upon the occurrence of a malfunction, storage means for storing the status signal in response to the sensing of a malfunction at a signature feeding station, means controlled by said status signal for rejecting the imperfect book at said reject station, inspection means for inspecting a chain space beyond said reject station and providing a signal if a book is present in said chain space, and means for comparing the signal from said inspection means with the status signal.
 2. A system as defined in claim 1 and further including stopping means responsive tO said comparison means for stopping the collating system when a book is present in a chain space from which the book should have been rejected or when a book is absent from a chain space from which the book should not have been rejected.
 3. A system as defined in claim 1 and further including counter means responsive to said comparison means for counting the number of times that a book is present in a chain space from which the book should have been rejected and absent from a chain space in which a book should be present.
 4. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book wherein said malfunction comprises either missing the feeding of a signature or the multiple feeding of a signature and said sensor means comprises first means for sensing the missed feeding of a signature and second means for sensing a multiple feeding of a signature, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station including first means for storing a maximum limit number of missed feeding malfunctions and second means for storing a maximum number of multiple feeding malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating each number of malfunctions registered in said counting means with the respective stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the respective stored limit number for that station.
 5. A collating system for producing different magazines composed of different predetermined combinations of signatures for different groups of subscribers classified in accordance with predetermined subscriber information, the system comprising a gathering machine having a gatherer conveyor with a plurality of chain spaces movable successively through a plurality of signatures feeding stations and adapted to receive signatures at said feeding stations whereby a magazine is formed in each chain space as the chain space moves through the feeding stations, said gathering machine comprising signature feed means at each of said stations, said gathering machine operating in cycles, each cycle of operation causing successive feeding of signatures from at least some of said signature feed means to make up each magazine, each of said signature feed means having instruction means for instructing the associated signature feed means to feed or not feed during each gathering machine cycle, file means for storing information in machine readable form identifying different subscribers with different predetermined combinations of at least some of said signature feed means to be instructed to feed during a machine cycle to provide the predetermined combination of signatures constituting the appropriate magazine for each subscriber, reading means for reading said file means and instructing feeding of said signature feed means in the predetermined combination required to provide the different magazines appropriate for the corresponding subscribers, manual switching means for each instruction means for disconnecting said reading means from said instruction means for each signature feeding means, and further comprising sensing means for sensing malfunctions separately at each of said signature feeding stations, and producing status signals accordingly, computer means comprising means receiving information based upon said signals for computing for each of said stations a rate of occurrence of malfunctons for a predetermined number of counted cycles of said gathering machine, sAid computer means further comprising means for computing when said rate of occurrence reaches a predetermined and stored limit, and first stopping means for stopping the system when said predetermined limit is reached, said system further comprising second stopping means responsive to said status signals for stopping the system when said sensing means senses a predetermined number at least one of successive malfunctions at a signature feeding station, and means for disabling said first stopping means and enabling said second stopping means upon actuation of said switching means to feed signatures when said signature feeding means is disconnected from said reading means, and further including storage means for storing said status signals, means controlled by said status signals for rejecting an imperfect book at a reject station, inspection means for inspecting a chain space beyond said reject station and providing a signal if a book is present in said chain space, and comparison means for comparing the signal from said inspection means with the status signal.
 6. A collating system for producing different magazines composed of different predetermined combinations of signatures for different groups of subscribers classified in accordance with predetermined subscriber information, the system comprising a gathering machine having a gatherer conveyor with a plurality of chain spaces movable successively through a plurality of signatures at said feeding stations whereby a magazine is formed in each chain space as the chain space moves through the feeding stations, said gathering machine comprising signature feed means at each of said stations, said gathering machine operating in cycles, each cycle of operation causing successive feeding of signatures from at least some of said signature feed means to make up each magazine, each of said signature feed means having instruction means for instructing the associated signature feed means to feed or not feed during each gathering machine cycle, file means for storing information in machine readable form identifying different subscribers with different predetermined combinations of at least some of said signature feed means to be instructed to feed during a machine cycle to provide the predetermined combination of signatures constituting the appropriate magazine for each subscriber, reading means for reading said file means and instructing feeding of said signature feed means in the predetermined combination required to provide the different magazines appropriate for the corresponding subscribers, and further comprising sensing means for sensing malfunctions separately at each of said signature feeding stations, computer means comprising means for computing for each of said stations a rate of occurrence of malfunctions for a predetermined number of gathering machine cycles, said computer means further comprising means for computing when said rate reaches a predetermined limit, and first means for stopping the system when said predetermined limit is reached.
 7. A collating system as defined in claim 6 and further comprising manual switching means for each instruction means for disconnecting said reading means from said instruction means for each signature feeding means, second means for stopping the system when said sensing means senses a predetermined number at least one of successive malfunctions at a signature feeding station, and means for disabling said first stopping means and enabling said second stoppping means upon actuation of said switching means to feed signatures when said signature feeding means is disconnected from said reading means.
 8. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfuncton at each signature feeding station which Would produce an imperfect book, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and wherein said malfunction comprises either missing the feeding of a signature or multiple feeding of a signature, and said sensor means comprises first switch means for sensing the missed feeding of a signature and second switch means for sensing the multiple feeding of a signature, and wherein said means for storing a maximum limit number includes means for storing a limit number of missed signatures and a limit number of multiple-fed signatures for each station, means for separately counting the number of missed signatures and the number of multiple-fed signatures at each station, and means for separately comparing the counts of missed signatures and multiple-fed signatures at each station with their respective stored limit numbers for stopping the system upon reaching the respective limit number.
 9. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, and means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and wherein said counting means and said comparison means comprise digital computer means.
 10. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing a malfunction at each signature feeding station which would produce an imperfect book, counting means for registering and counting the sensed malfunctions for a predetermined number of machine cycles, data storage means for each feeding station for storing a maximum limit number of malfunctions for the predetermined number of machine cycles, comparison means for receiving and comparing data indicating the number of malfunctions registered in said counting means with the stored limit number of malfunctions, means responsive to said comparison means for stopping the system when the number of malfunctions which occurred at any station equals the stored limit number for that station, and feed control means for controlling said signature feed means to feed or not to feed a signature to said gatherer conveyor at each station, said feed control means including digital computer means for controlling said feed control means at each station.
 11. A collating system as defined in claim 10 and wherein said feed control means further comprises manually settable means for controlling said signature feed means to feed or not to feed, including seLection means for individually placing said signature feed means either under control of said digital computer means or under control of said manually settable means.
 12. A collating system for forming a book from a plurality of signatures, said system comprising a gatherer conveyor movable successively through a plurality of signature feeding stations and adapted to receive signatures at said feeding stations, a signature feed means at each feeding station, sensor means for sensing occurrence of a malfunction feed at each signature feeding station which would produce an imperfect book, first counting means for counting a predetermined number of machine cycles, second counting means for registering and counting the number of sensed malfunction feeds during said predetermined number of machine cycles, said second counting means being capable of registering and counting said malfunction feeds when said malfunction feeds occur non-contiguously among intervening correct feeds, data storage means for each feeding station for storing a maximum limit number of malfunction feeds for said predetermined number of machine cycles, comparison means for comparing said stored limit number with data indicating said number of malfunction feeds registered in said second counting means since the start of said predetermined number of machine cycles, and means responsive to said comparison means for stopping the system when the number of malfunction feeds which occurred at any station equals the stored limit number for that station.
 13. A collating system as defined in claim 12 further including feed control means for controlling said signature feed means to feed or not to feed a signature to said gatherer conveyor at each station.
 14. A collating system as defined in claim 12 and wherein said malfunction comprises either missing the feeding of a signature or the multiple feeding of a signature, and said sensor means comprises first switch means for sensing the missed feeding of a signature and second switch means for sensing the multiple feeding of a signature.
 15. A collating system as defined in claim 12 and wherein said first counting means comprises means for resetting said second counting means to start its count anew when said predetermined number of machine cycles is reached.
 16. A collating system as defined in claim 12 and further comprising shutdown means responsive to said sensing means to actuate said means for stopping upon occurrence of a predetermined number at least one of uninterrupted successive malfunctions at each individual feeding station, and switching means for each individual feeding station for selectively making said means for stopping responsive either to said comparison means or to said shutdown means.
 17. A collating system as defined in claim 12 and wherein said second counting means comprises means capable also of registering and counting malfunction feeds that occur contiguously without intervening correct feeds, whereby said number of malfunction feeds registered in said second counting means includes both non-contiguous and contiguous malfunction feeds. 